from re import sub,search

def stemSuffix(word,selector="regular"):
    '''
    Stemmes the predefined suffixes from a word.
    
    @param word: The word to be stemmed.
    @return: The word after stemming.  
    '''
    word = word.lower()
    if (not search(r'sses$',word)   is None):   return sub(r'sses$',    'ss'    ,word)
    if (not search(r'ies$',word)    is None):   return sub(r'ies$',     'i'     ,word)
    if (not search(r'ss$',word)     is None):   return sub(r'ss$',      'ss'    ,word)
    if (not search(r's$',word)      is None):   return sub(r's$',       ''      ,word)
    if (not search(r'.+eed$',word)  is None):   return sub(r'eed$',     'ee'    ,word)
    if (not search(r'ed$',word)     is None):   return sub(r'ed$',      ''      ,word)
    if (not search(r'ing$',word)    is None):   return sub(r'ing$',     ''      ,word)
    if (not search(r'at$',word)     is None):   return sub(r'at$',      'ate'   ,word)
    if (not search(r'bl$',word)     is None):   return sub(r'bl$',      'ble'   ,word)
    if (not search(r'iz$',word)     is None):   return sub(r'iz$',      'ize'   ,word)
    if "regular" == selector: return word
    # porters' 2nd step
    if (not search(r'.+ational$',word)  is None):   return sub(r'ational$', 'ate'   ,word)
    if (not search(r'.+tional$',word)  is None):    return sub(r'tional$',  'tion'  ,word)
    if (not search(r'.+enci$',word)  is None):      return sub(r'enci$',    'ence'  ,word)
    if (not search(r'.+anci$',word)  is None):      return sub(r'anci$',    'ance'  ,word)
    if (not search(r'.+izer$',word)  is None):      return sub(r'izer$',    'ize'   ,word)
    if (not search(r'.+abli$',word)  is None):      return sub(r'abli$',    'able'  ,word)
    if (not search(r'.+alli$',word)  is None):      return sub(r'alli$',    'al'    ,word)
    if (not search(r'.+entli$',word)  is None):     return sub(r'entli$',   'ent'   ,word)
    if (not search(r'.+eli$',word)  is None):       return sub(r'eli$',     'e'     ,word)
    if (not search(r'.+ousli$',word)  is None):     return sub(r'ousli$',   'ous'   ,word)
    if (not search(r'.+ization$',word)  is None):   return sub(r'ization$', 'ize'   ,word)
    if (not search(r'.+ation$',word)  is None):     return sub(r'ation$',   'ate'   ,word)
    if (not search(r'.+ator$',word)  is None):      return sub(r'ator$',    'ate'   ,word)
    if (not search(r'.+alism$',word)  is None):     return sub(r'alism$',   'al'    ,word)
    if (not search(r'.+iveness$',word)  is None):   return sub(r'iveness$', 'ive'   ,word)
    if (not search(r'.+fulness$',word)  is None):   return sub(r'fulness$', 'ful'   ,word)
    if (not search(r'.+ousness$',word)  is None):   return sub(r'ousness$', 'ous'   ,word)
    if (not search(r'.+aliti$',word)  is None):     return sub(r'aliti$',   'al'    ,word)
    if (not search(r'.+iviti$',word)  is None):     return sub(r'ivity$',   'ive'   ,word)
    if (not search(r'.+biliti$',word)  is None):    return sub(r'bility$',  'ble'   ,word)
    
    return word

def isStopWord(word,selector="small"):
    '''
    Checks whether the word is a stop-word.
    
    @param word: The word to be classified.
    @return: True iff the received word is a stop-word.
    '''
    
    stopWordsSmall = ["a", "an", "and", "are", "as", "at", "be", "but", "by", "for", "if", "in", "into", "is",\
                 "it", "no", "not", "of", "on", "or", "such", "that", "the", "their", "then", "there",\
                 "these", "they", "this", "to", "was", "will", "with",\
                 "few", "so", "also"]
    stopWordsGrande = ["a", "about", "above", "above", "across", "after", "afterwards", "again", "against", "all", \
                 "almost", "alone", "along", "already", "also","although","always","am","among", "amongst", \
                 "amoungst", "amount",  "an", "and", "another", "any","anyhow","anyone","anything","anyway", \
                 "anywhere", "are", "around", "as",  "at", "back","be","became", "because","become","becomes", \
                 "becoming", "been", "before", "beforehand", "behind", "being", "below", "beside", "besides", \
                 "between", "beyond", "bill", "both", "bottom","but", "by", "call", "can", "cannot", "cant", \
                 "co", "con", "could", "couldnt", "cry", "de", "describe", "detail", "do", "done", "down", \
                 "due", "during", "each", "eg", "eight", "either", "eleven","else", "elsewhere", "empty", \
                 "enough", "etc", "even", "ever", "every", "everyone", "everything", "everywhere", "except", \
                 "few", "fifteen", "fify", "fill", "find", "fire", "first", "five", "for", "former", "formerly", \
                 "forty", "found", "four", "from", "front", "full", "further", "get", "give", "go", "had", \
                 "has", "hasnt", "have", "he", "hence", "her", "here", "hereafter", "hereby", "herein", \
                 "hereupon", "hers", "herself", "him", "himself", "his", "how", "however", "hundred", "ie", \
                 "if", "in", "inc", "indeed", "interest", "into", "is", "it", "its", "itself", "keep", "last", \
                 "latter", "latterly", "least", "less", "ltd", "made", "many", "may", "me", "meanwhile", \
                 "might", "mill", "mine", "more", "moreover", "most", "mostly", "move", "much", "must", "my", \
                 "myself", "name", "namely", "neither", "never", "nevertheless", "next", "nine", "no", "nobody", \
                 "none", "noone", "nor", "not", "nothing", "now", "nowhere", "of", "off", "often", "on", "once", \
                 "one", "only", "onto", "or", "other", "others", "otherwise", "our", "ours", "ourselves", "out", \
                 "over", "own","part", "per", "perhaps", "please", "put", "rather", "re", "same", "see", "seem", \
                 "seemed", "seeming", "seems", "serious", "several", "she", "should", "show", "side", "since", \
                 "sincere", "six", "sixty", "so", "some", "somehow", "someone", "something", "sometime", "sometimes", \
                 "somewhere", "still", "such", "system", "take", "ten", "than", "that", "the", "their", "them", \
                 "themselves", "then", "thence", "there", "thereafter", "thereby", "therefore", "therein", "thereupon", \
                 "these", "they", "thickv", "thin", "third", "this", "those", "though", "three", "through", "throughout", \
                 "thru", "thus", "to", "together", "too", "top", "toward", "towards", "twelve", "twenty", "two", "un", \
                 "under", "until", "up", "upon", "us", "very", "via", "was", "we", "well", "were", "what", "whatever", \
                 "when", "whence", "whenever", "where", "whereafter", "whereas", "whereby", "wherein", "whereupon", \
                 "wherever", "whether", "which", "while", "whither", "who", "whoever", "whole", "whom", "whose", "why", \
                 "will", "with", "within", "without", "would", "yet", "you", "your", "yours", "yourself", "yourselves", "the"]
    if "small" == selector:
        return word.lower() in stopWordsSmall
    if "grande" == selector:
        return word.lower() in stopWordsGrande
    return False